German Patent No. DE-PS 169 943 discloses a staple wire reel of the generic type in which a spring-loaded brake element, resting on the outer turn of wire, is provided. This brake element is attached to a protective cover which partially surrounds the staple wire reel when installed, and serves to brake the rotation of the reel and prevent uncontrolled detachment of the leading end of the wire. Outside the protective cover, however, the leading end of the wire on the staple wire reel is not secured against detachment, so that it can become bent, and there moreover exists a risk of injury from the protruding wire end.